Fuel mixture supply control for the internal-combustion engines of motor vehicles



Dec. 28, 1937. A SMART I 2,103,700

- FUEL MIXTURE SUPPL CONTROL FOR THE INTERNAL COMBUSTION ENGINES OF MOTOR VEHICLES Filed Dec. 13, 1935 3 Sheets-Sheet l Jana/41f INVENTOR ATTORNEYS Dec. 28, 1937. 2,103,700

.-SMART FUEL MIXTURE SUPPLY CONTROL FOR THE INTERNAL COMBUSTION ENGINES OF MOTOR VEHICLES Filed Dec. 13, 1935 SSheets-Shept 2 FIG. 5.

dw vuww ,qfimazb," INVENTOR BY 7014M ATTORNEYS Dec. 28, 1937. I A. SMART 2,103,700

FUEL MIXTURE SUPPLY CONTROL FOR THE INTERNAL comaus'uou ENGINES OF MOTOR vznxcmas Filed Dec. 15, 1935 s Sheets-Sheet s as M FIG. II. b a Ha, I. Y i

IOI 1 H9 99 l is as O .flsa 5 I23 01 9 "x 1 52 $92 i r I;| 4.. A "5 1a H us m Q 8 1v 6 96 mo 1e 99 9a 13 1' III as 9 I k 1 7 I I04 19 I05 7' u 99 \4////\ v 96 I FIG. 8, '2 8 L\ 1 N VE'H TOR BY Mm ATTO R N E vs Patented Dec. 28, 1,931

UNl'TED- STATES PATENT OFFICE emu coN'raoL roa 'rna m1.- mx'rvaa INTERNAL-COMBUSTION Moron vsmcnss exams or Algernon Smart. Newcastle-npon-Tyne, England Anlicsuen December 1:, ms, Serial re-" 54,239 In Great Britain December 15, 19:4

80lalms.

celerator pedal, the closing of said valve, when pressure is removed from said pedal, being limited so that a predetermined minimum supply oi mixture passes to the engine even when the latter is merely idling. This position oi the throttle valve is hereinafter termed idling position.

In general, the object of the present invention is to provide novel and useful fuel-mixture control means whereby to eliminate the waste of fuel to idling position, and thereby preventing the flushing-out oi the engine cylinders by rich fuelmixture and the consequent waste of lubricating oil.

With this and other objects in view, as will appear as the description proceeds, my invention consists in the novel methods of operation, features o i go nstruction and combinations and arrangements of parts hereinafter described and particularly defined in the claims appended to this specification.

The accompanying drawings illustrate examples oi fuel-mixture supply controls in acoordance with my invention. In the drawings,

Figures 1, 2 and 3 are diagrammatic elevations respectively illustrating diilerent operative positions 01' one i'orm of mechanically-operated control means;

Figure 4 is a vertical section illustrating an alternative form of mechanically-operated control means; 1

Figures 5- and 6 illustrate an example of electro-magnetically-operated control means, Fig. 5 being a diagrammatic view showing-the connections. and Fig. 6 a section on the line in Figures 7.8 and 9 illustrate an example of suction-ac'tuated control means, Fig. 7 being a sec- .tional elevation, 8 an elevation at right angles thereto and half in section on the line H .in Fig. 'I, and Fig. 9 a section on the line 3-3 in Fig. 8:

Figure 10 is a similar view to Fig. 7 illustrating an alternative form of suction-operated control means; and

Figure 11 is a transverse section illustrating a further alternative trol means.

Referring first to Figs. 1, 2' and 3 of the said drawings. inthe mechanical device therein illustrated, a is the throttle valve disposed in the pipe b which is the pipe leadlng i'rom the carburetter to the engine. On the spindle of the valve a is fixed a lever d, e to the end ofthe arm so! which is pivotally attached a rod j which is connected to the accelerator pedal. 0, h is the movable stop and is pivoted at q on 9. lug on the pipe b, said stop being provided with a spring i which is coiled around and anchored to its pivot. v m is a headed rod connected to the clutch mechanism of the engine. The rod mslides through a pin it rotatable in the arm n oi the stop. c is a roller attheendo! thearme,andpisanair inlet valve mounted in a pocket b open to, the pipe I), said valve being normally held closed by the spring 1'. s is an adjustable set screw limitiorm oi suction actuated coning the movement of the stop a, h in one'direction. said set screw being supported by the cylinder block I: or other adjacent ilxed part of the celerator pedal, the throttle valve a being shown as fully open, the air valve 9 closed, and the arm a oi the stop held by its spring j against the head of the clutch rod m. When, however, engine propulsion is not required (for example, where a vehicle is running downs hill), the pressure on the accelerator pedal is withdrawn and the members take up the position shown in Fig. 1, thc'throttle valve a being fully closed and the supply oi fuel-mixture to the engine wholly shutoil. Atthesametimetheairvalvepisheld openbythearmdoi'theleveronthethr'ottle valve spindle to allow the engine to draw in air. so long as the engine is connected to the transmission system, the engine is driven by the vehicle, and fuel mixture can be again supplied to the cngine'when desired by presslng'down the accelerator pedal to return the members to the" positions shown in Fig. 3 with the throttle valve a open and the air valve 9 closed.

Ii now the clutch mechanism is'operated to dis- "connect the engine irom'the transmission system of the'vehicle while the accelerator pedal is not I 2,1oa,voo

oi the lever on the throttle valve spindle to move the throttle valve into its idling position as 8110711411153. 2, in which position it is retained by the encasement of the nose the arm in with the roller-c on the arms. the set screw s limiting the downward movement 01 the stop h. sumcient fuel-mixture is now allowed to pass into the pipe b to ensure that the engine idles and stallthe valve :1 in its idlingposition.

It will be seen that, with the device illustrated in-l 'igs. 1 to 3, the throttle valve is can be fully clued and the air valve p opened only while the engine, is connected to the power-transmission supply oi suiilelent fuel-mixture to keep the en- I gine running slowly.

Alternatively, and as illustrated in Pig. 4, I

may provide a by-pass t around the throttle valve :1 in the pipe b, and provide said by-pass with an air valve p-held cloudby an adimtable spring randwithavalveupressedopenbyanadjustablespring o. Thevalvepcontrols an air inletw in the by-pass fitting 3, and the valve a is connectedbyacableytothemovlngmember of a centrifugal governor driven by the engine oi. the

vehicle. The governor is not illmtrated and may be of any well-known type of speed governor. It is adjusted so that it automatically applies a pull t.'- the cablepwhichovercomes the resist- *anceoithespringoandclosesthevalveawhen thespeedoi'theemineexceedsitsidiingspeed.

It will therefore be seen that the by-pass t is open only when the engine is revolving at idling speed orless. Whenthethrottlevalveaisiullyclosed andthe speed oi. the engine is greater tmn idling only when the throttle valve 4: and the by-pass valveaarebothclosed. Whenthespeedotthe engineiallstoidiingspeed.thevalveaisre opened by itsspringandaslmplyoi fuel-mixture passesthroughthe by-pasttothe engine which issuihcienttopreventstalling.

Reterringnowtol'igs.5and6.inthe electromagnetic device therein illustrated, I interpose a supplementary throttle valve il between the carburettor and the induction manifold, said vaivebeingmounted inahousing i2 capable of beinginsertedinthepipeconnectingsaidparts, andlprovideanair pasage ii-inthespindle ll of said valve, said passage opening on the engine .sidethereoi'andleadingiromachamber llina casing ltattachedtothehm singllandcontaining an electro-magnet 11. The core ll of saidmagnetisconnectedbyalinklltoonearm of clever 20 on the spindle ll, the other arm of said lever being provided with a face 2] formping a valve coacting with an air port 22 leading from the space around the magnet II which is open to atmosphere through an air inlet 23 as shown inFlg. 6. 24 is a spring within the magnet which projects its core II when the magnet is not energized. when the core is projected, the supplementary valve II is fully open and the air port 22 is closed by the valve 1i as shown.

One end of thecoil oi the magnet i1 is connected to an earthed terminal '4 by a wire II, and the other. end of said coil is connected by a wire 26 to one terminal 21 01 an interlocking switch the feed terminal 28 of which is connected by a wire 29 through a master switch 3. on the dashboard of the vehicle and a fuse 3! to the usual battery 32 on the vehicle. The other terminal 33 of the interlocking switch is connected by wires II and through the coil of a solenoid I! to one terminal li e! a two-way switch, the common terminal 31 orwhich is connected to the earthed terminal 64 by a wire ll, its other terminal I! being connected by wires I and through the coil of a second solenoid 4| to the terminal 21 of the interlocking switch which is connected to the magnet H. The coil 01' the solenoid i is also connected by a wire I! to the terminal ll of a one-way switch, the other terminal ll of which is connected to the earthed terminal 04 by a wire 45;

The one-way switch 43, II is normally-kept closed by a. spring It acting through a pivoted rocker l1, but'is opened when the clutch lever (indicated at ll) or equivalent mechanism engages and liits a finger l! on said rocker which occurs when the clutch is engaged. The two-way switch 36, 31, 39 is actuated by projections N on a pivoted rocker provided with a finger 5! in the way of the accelerator pedal lever which isv indicated at 53, a spring 54 holding said linger clear of said lever when the pedal is depressed. The projections 5| co-act with spring contacts 55; 56;. 51 projecting from the terminals 3', 31, 39 respectively. "The spring contact I! is bowed between the terminal 36 and an extension a thereoi so that it remains in either the raised SI, 81 are in engagement when the finger ll B in its normal positionas shown, 1. e. the terminal 39 is earthed when the accelerator pedal is decited.

The panels 55, it carrying the one-way switch 0, l4 and the two-way switch a, II, II respectively are mounted on parts of the vehicle conveniently adjacent to the clutch lever 4. and accelerator pedal lever 53 respectively, and the panel 61 carrying the solenoids II, I and the interlocking switch 21, 2!, 33 may be mounted on the dashboard or in other convenient position.

Fig. 5 shows the position of the switches when the engine is connected to the transmission system of the vehicle and the accelerator pedal is depressed for normal running, and in this posi- I 3,100,700 tion the circuit of the magnet I1 is broken by reason of the gap between the contact and the terminal 21-. During normal running theretore the supplementary throttle valve II is held open by the spring it within the magnet and the air valve 2| closes the air inlet 22, the supply of fuel-mixture to the engine being regulated by the throttle valve under the control of the accelerator pedal as customary.

Itwillbe seenthat,themasterswitch "bein closed, the circuit of the magnet I1 is completed only when the contact 00 is engaged with the terminal 21, and to cause suchengagement it is necessary to energize the solenoid 00. This occurs when engine propulsion is not required and pressure on the accelerator pedal is withdrawn, the lever 00 then pushing up the finger I! whereupon the rocker II depresses the contact 00 into engagement with the contact II to close the circuit of the solenoid II through the terminals 03. the contact II and the terminals 20. The solenoid 00 at once attracts its armature 02 and causes its finger 00 to engage the contact 00 with the terminal I! to close the circuit of the magnet II and: at the same time to release the finger 0|. 'Ihe consequent fall of the armature 00' disengages the contact 00 from the terminal 00 and the circuit of the solenoid II is broken but its armature" is held in its raised position by the tip of the finger 0| engaging behind the finger 00, and the engagement of the contact 00 with the terminal 21 and the feed to the magnet II are maintained. Thus. so long as there is no pressure on the accelerator pedal, the magnet ll closes the supplementary throttle valve II to shuboi! the supply oi incl-mixture to meanneandopenstheairinletfltoallowairtoenter the. induction manifold which condition persists while the engine remains connected to the transmission system. Subsequent depression of the accelerator mdal however frees the finle'r I! and allows the contact 00 to disengage the contact 00 and engage the contact I! whereupon the circuit of the solenoid ll is completed through the' terminal I! and its armature 00 is attracted. The movement of the armature 00 releases the ILwhllethemagnetJlis energiaedandthe supplementaryvalve ll closed 06 open,theengineisdisconnectediromthepowerduction pipe b on the engine side of the usual' throttle valve 41 and being opened and closed by a connecting rod 10 pivotally attached to a l II on the valve-and to a piston I2 in a cylinder 13 formed in said housing. The lower end of the cylinder is open to the induction pipe on the engine side of the valve, and a spring I0 is provided within the piston 12 which tends to keep it raised and consequently to hold open the valve i I. ll, I0 are air ports in the walls of the cylinder, and 11 is a groove around the piston 12 which registerswith said ports when the piston is in its bottom position and the valve II is closed as shown. when the valve ii is .open, the ports I0, 10 are covered by the piston.

A passage 10 connects the space above the. Diston 12 to a chamber 19 in which .is a valve 00 disposed between seatings 8|, 02 so as to alternatively close passages 03, 04 leading to the chamber I0. The passage 03 leads from below the valve 00 to a chamber in an extension 06 oi the housing l2, said chamber containing a valve 01 controlling an air inlet 00. The valve 01 has a projecting spindle 09, and an adjustable stop 00 on an arm 0| on the spindle 02 of the throttle valve 4: co-acts with the end of said spindle to force it and the valve 01 inwards againsta spring 00 in the chamber to admit air to'said chamber. The passage 04 leads from above the valve 00 to a passage 04 in the back of the housing I! communicating with the induction pipe on the engine side of the valve ii. The pindle 05 of the valve 00 is fitted with a diaphragm 00 the periphery of which is held between a seating 01 aroimd the upper end of the housing II and a cover 00 screwed .thereonto, said cover enclosing a spring 09 which extends between collars III, III on an extension I 02 of the spindle II. The collar I00 bears on the upper face oi the diaphragm 00 and presses said diaphragm onto a collar I00 around the spindle 95, and the collar III is received in a cap I04 screwed into the cover 00. The cap is adjustable in said cover to vary the compression of the spring 09 and, after adjustment, is locked in position by the nut I00.

The chamber I00 below the diaphragm 0B is connected by a passage I01 to the air passage 03. and a small aperture I00 (Fig. 8) connects said chamber to the passage 00. A port I00 is provided in the back of the cylinder 13 which leads to the passage 00, said port being positioned so that the air groove I'l around the piston 12 registers with said port when the piston is in-its bottom position, i. e; when the supplementary throttle valve l I is closed and said groove registers with the air ports l0, II. An adjustable screw Ill-is provided in the wall of the housing I! to control the exit oi the port I00 and'hence the admission of air into the passage 00'.

normal running when the supply of fuel-mixture to the engine is controlled as customarily by the accelerator pedal through the throttlevalvea,thepistonl2israisedbyits spring II and the supplementary -throttle valve H is held open while the air ports II, I0 are closed I said piston.

when pressure withdrawn from the accelerator pedal and the throttle valve assumes its idling position, the arm 0| swings to the left and its stop 00 stiika the spindle 00 and presses the valve 01 inwards to admit air to the passages 00, I0? andthe chamber I00 below the diaphragm l0. The interior of the cover 00 is open through the passage 00 to the suction on the engine side oi the supplementary valve II which suction tends to cause the diaphragm to raise thevalve II, but

- the throttle valve is opened vto enable the engine said tendency is resisted by the spring 99. The spring 99 is adjusted so that the suction caused by the engine when it is merelyidling is insuiiicient to overcome the resistance of said spring, but the increased engine suction, which occurs when the throttle valveis in idling position and the engine is driven by the'vehicle at a greater speed than the normal idling speed, acts upon the upper side of the diaphragm and permits the atmospheric pressure in the chamber I06 to raise the valve 80 whereupon air passes through the chamber 19 and passage 18 .to the cylinder I3. The consequent atmospheric pressure above the piston 12 overcomes the resistance of the spring 14 and forces down said piston thus closing the supplementary valve II to shut-of! the supply of fuel-mixture to the engine and at the same time admitting air to the engine side of said supplementary valve through the ports 19,- 18. This is the condition shown in Figs. '7 and 8 and persists so long as the engine remains connected to the power-transmission system of the vehicle and its speed is greater than the normal idling speed, it being understood that the size of the air ports '75, is. insufficient to admit. such a quantity of air as to destroy the suction effect produced by.

the engine on the engine side of the valve ll.

Should the speed of the engine fall until it approaches idling speed due to the slowing down of the vehicle or the de-clutching of the engine, the intensity of the engine suction correspondingly decreases until the spring 99 overcomes the suction efiect on the diaphragm whereupon said diaphragm is depressed and lowers the valve I onto its seating 8! thus shutting-oifthe chamber 19 from the air passage 83 and opening it to engine suction through the passages 84, '94.

tion through thechamber l9 and passage 18 and allows the spring 14 to raise the piston and shutoff the air ports 15, i6, re-open the supplementary valve II and so admit fuel-mixture to the engine through the throttle valve a which is in its idling position.

If, while the supplementary valve II is closed.

to develop power, it is necessary at once to cause the re-opening of the valve II and the closing of the air ports'15, 16, and it will be seen that the re-opening of the throttle valv'e'disengages the press the diaphragm and move over the valve",

toopen the space above the piston 12 to engine suction and allow the spring 14 to raise the piston thus shutting-oil the air ports'li, It and re-.-

opening the supplementary valve II.

In operation, when the supplementary valve H has closed owing to the abnormal suction in the induction pipe I) when the throttle valve :1 is in idling position and the vehicle is driving the engine at more than idling speed,.,said suction effect may increase if the air supply'to the engine through the ports 15, I6 is less than the supply of fuel-mixture through the throttle valve 11 in idling position. The uncompensated eilect of said increased suction on the diaphragm 99 would The change-over of the valve 80 opens the space in the cylinder 13 above the piston 12 to engine suc-' aioavoo prevent there-opening of the supplementary valve Ii until the engine speed fell below idling speed and would tend to cause the engine to stall, and the passage Ill and set screw III are provided to provide the n compensation. By adlusting the screw HO, an amount of air is allowed topass fromthe groove 11 in the piston 12 through the e ll! into thepassage 94 and so to the interior of the cover 98 which ensures that the spring 99 depresses the diaphragm 96 to cause the valve '80 to move over whenthe speed of the engine isjust greater than its idling speed.

Fig. illustrates an alternative arrangement to that shown in Figs. '1 to 9. In Fig. 10'the supplementary throttle valve II and the air inlet valve 81 are dispensed with, and the throttle valve a is completely closed when pressure is withdrawn. from the. acceleratorpedal. The spring-loaded diaphragm 99 and the valve 80 are retained, the passage "below the latter and the chamber i 06 below-the diaphragm being open directly to atmosphere. The spring piston II, as well as controlling the air ports l5, I6, is provided with a plunger Ill controlling aby-pass I ll leading from the carburettor side of the throttle valve to the engine side thereof. 3 is a fuel supply jet, and I 14 is an adjustable screw whereby the opening of the by-pass can be adjusted as required.

R It will be seen that while thethrottle valve a g is open, the piston 12 is raised by its spring and the air ports 15,16 are closed while'the plunger.

II I is withdrawn from the by-pass llfso that fuel-mixture is drawn into the induction pipe b past the throttle valve a and, to some extent, through the by-pass I l 2. When the throttle valve isclosed as shown in Fig. 10, the by-pass allows suflicient mixture tov pass to the induction pipe to keep the engine idling. but increased engine suction on the engine side of the valve a'when the vehicledrives the engine, is applied through the passage 94 to the interior of the cover '98 above the diaphragm 96 and allows the atmospheric pressure in the chamber I08 toraise the dia phragm and hence the valvelil, thus admitting air above the piston 12 to overcome the resistance of its spring and force down said piston, whereupon 'air is admitted through the ports I5, 16 to the. engine side of the valve a-and the plunger HI closes the by-pass 2. This condition persists until the suction on the engine side of the valve it decreases owing to reduced engine speed or the valve a is reopened'by the accelerator pedal. Reduction of suction below the minimum for which the spring 99 is adjusted allows said spring to pressdown the diaphragm Stand change-over the valve 80 to shut-off air pressure and 8) or a by-pass such as 'l l2 Fig'..10) I may,

as illustrated in Fig. 11, utilize the diaphragm 96 to control a needle-valve I I3 in the passage iii of a. nozzle like member I I5 screwed into the car-.

burettor body 6 so as to project into the fuelsupply pipe ll! leading from the float chamber llilto the fuel jet N9, the interior of-the cover -98 of said diaphragm being connected by a pipe I20 to the induction pipe I) on the engine sideof the throttle valve a. In this arrangement, the spring 99 supporting the diaphragm is adjusted so that the increased engine suction due to the engine being driven by the vehicle when the throttle valve is in idling position allows the pressureon the upper side of the diaphragm. 9 to overcome the resistance of the spring and close the head I23 of the needle valve 3 over the exit from the passage Ill and so shut-oil iuel to the jet I IS, the fuel continuing to be shut-off so long as said increased engine suction persists. No additional air inlet need be provided with this arrangement as air alone is drawn into the induction pipe through the throttle valve while the supply of fuel to the jet 9 is shut-oil.

.A vehicle fitted with any of the above mentioned means for controlling the supply offuelmixture to its engine can be allowed to run down an incline under its own momentum with its engine clutch engaged, and, while the engine is connected to the power-transmission system of the vehicle or, where suction-actuated or governor-controlled means are provided, so long as the speed of the engine exceeds its idling speed, no fuel isconsumed and the engine draws in air only, the supply of mixture to the engine under the control of the accelerator pedal being automatically restored on actuating said pedal, or a supply of mixture suflicient to prevent stalling of the engine being automatically restored without actuating said pedal when the. engine is de-clutched or, in thecase of suction-actuated or governor-controlled means, when its speed falls and approximates its idling speed.

What I claim as my invention and desire to secure by Letters Patent is: i

1. Apparatus for controlling the supply of fuel.- mixture to the internal-combustion engine .of a motor vehicle comprising means for completely shutting-off said supply and simultaneously. ad-

mitting air in lieu thereof while the engine is connected to the transmission system or the vehicle and is being driven thereby, said means being associated with means for restoring a supply of mixture and simultaneously shutting-oi! said air which latter means function automatically to prevent the engine stalling when the vehicle ceases to drive the engine.

2. Apparatus according to claim 1, wherein the operation of the mixture shutting-off means controlled by the varying engine. suction in the induction pipe.

3. Apparatus according to claim 1, wherein the f mixture shutting-of! means and the air admission means are operatively associated with'the accelerator pedal or equivalent device, and the restoring oi the vfuel-mixture supply is eflected automatically by apparatus controlled by the varying engine suction in the induction pipe.

4. Means as claimed in claim 1 automatically actuated by the engine suction in the induction pipe whereby the fuel-mixture supply to the engine is shut-oi! and air is admitted to or allowed to enter the induction pipe when the engine suction in said pipe exceeds that produced when the engine is idling on a minimum supply of fuel-mixture, said means automatically operating 'to exclude said admitted air and to re store said mixture supply when the throttle valve is opened and also when the engine suction in the induction pipe falls until it approximates that produced when the engine is merely idling.

5. Means as claimed in =,claim 1 comprising a supplementary throttle valve in the induction pipe, the closing of said valve being effected by excess of engine suction over that producedwhen the engine is idling, and being simultaneous with pipe on the engine side of said supplementary valve.

. the opening of an air inlet into said induction 6. Means as claimed in claim 1 wherein a supplementary throttle valve in the induction pipe scribed, by a spring-loaded piston to which atmospheric pressure or engine suction is applied under the automatic control or a'valve actuated by the intensity of the engine suction in the induction pipe on the engine side of said supplementary valve.

7. Apparatus according to claim 1 comprising a by-pass around'the throttle valve in the induction pipe, means controlled by the engine suction on the engine side of the throttle valve for opening'and closing a valve in said by-pass and ior admitting air to said induction pipe when the engine suction exceeds a predetermined amount.

8. Apparatus according to claim 1 comprising a by-pass around the throttle valve in the induc tion. pipe, means controlled by the engine suction on the engine side or the throttle valve for opening and closing a valve in said by-pass and for admitting air to said induction pipe when the engine suction exceeds a predetermined amount, said means comprising a spring-loaded piston to which atmospheric pressure or engine suction is applied under the automatic control of a valve actuated by the intensity of engine suction in the induction pipe on the engine side of said throttle valve.

ALGERNON SMART. 

